For producing a composite comprising metal members or ceramic members, sealing glass is widely used as a joining/sealing material for joining/sealing such members to form a composite.
As such sealing glass, glass frits processed in the form of a powder, a glass paste having such glass frits formed into a paste form, or a green sheet (glass sheet) having such glass frits formed into a sheet form may typically be used. That is, in a case where plane parts are to be joined, the glass paste or the green sheet may be used in many cases, and in a case where three-dimensional parts are to be joined, the glass frits may be used in many cases.
In recent years, sealing glass which can be used for sealing members of SOFC and which is operated at a temperature of from 700 to 1,000° C. is demanded. As such sealing glass for SOFC, non-alkali glass comprising, as represented by mass %, from 10 to 30% of SiO2, from 20 to 30% of B2O3, from 10 to 40% of CaO, from 15 to 40% of MgO, from 0 to 10% of SrO+BaO+ZnO, from 0 to 5% of Al2O3, from 0 to 5% of La2O3 and from 0 to 3% of RO2 (R is Zr, Ti or Sn) has been proposed (Patent Document 1).    Patent Document 1: JP-A-2007-161569